Solar energy panels have been known and used for a number of years, however they have become more interesting lately due to the increasing energy prices, environmental concerns, and an accelerating development of the production of solar cells for electric energy generation.
Solar energy has an energy density of approximately 1 kW/m2 at perpendicularly incident sunlight, distributed across a wide spectrum comprising infrared, visible, and ultraviolet light. This received energy may be utilized in several ways, among other by semiconductor based solar cells for electric current generation, and solar energy collectors for heating a medium for heating purposes.
Solar cell panels designed as roofing tiles are known, see U.S. Pat. No. 5,986,203; “Solar cell roof tile and method of forming same”, disclosing roofing tiles comprising a solar cell, and U.S. Pat. No. 5,768,831; “Rooftile support for photocell panel”, disclosing roofing tiles wherein a solar cell is provided onto each roof tile.
Solar collectors for roof mounting are known, ref. U.S. Pat. No. 4,202,319; “Building roof with solar collector”, disclosing roofing tiles comprising a solar collector, and U.S. Pat. No. 4,083,360, disclosing a solar energy collecting system wherein translucent roofing tiles allow sunlight through to an absorbing sheet, wherein pipes with a liquid heat medium are provided to carry the heat.
The problems with the known art and the products on the markets are many:
The utilization factor is low, approx. 10% for solar cells, and the efficiency is reduced when the temperature rises.
For solar energy collectors the nature of energy is heat and not electrical energy, this limits the area of usability and the amount of energy which may be utilized in practice;
The complexity is high, and installation is preferably performed by specialists, this limits the spread in the market, especially in the do-it-yourself market;
Solar cells and solar collectors are fragile, which requires care at the production, installation, and maintenance such as for instance while removing snow from roof.
It is therefore a need for a solution which easily may be produced and installed, and which is energy efficient.